1. Technical Field
This invention relates to disk drives and more particularly to disk drive suspensions. In a particular aspect, the invention relates to novel mounting of flexible electrical conductors on suspensions using the flexure and load beam as cooperating clamp members to mechanically support the flexible conductor so as to retain the flexible conductor in place without the use of glues or other bonding expedients.
2. Background Art
The positioning of conductor wires, and of flexible conductors, laminates of conductive layers and plastic film, has been accomplished typically by adhering the conductor in place. This requires precision placement of the flexible conductor in manufacturing to register with the application of the adhesive, is time-consuming and source of defects.
It is known to use twisted wire pairs for electrical connection to the slider in a suspension. In this arrangement very thin copper wires with gold plating are ultrasonically bonded to gold plated pads on the slider to connect the slider to the pre-amp so that the head an perform reading and writing from and to the disk.
The continual diminution in size of sliders increases the effect of unwanted forces and moments from the wires modulating the flying attitude of the slider. Changes in wire length may change wire stiffness. Changes in wire orientation may change the moment on the slider exerted by the wire. Either change will affect flying height, and in the case of large moments and biases, there can be adverse effects on the reliability of the head and recording media.
In place of wires certain supported flexible conductors have been employed; these include a laminate of conductive layers, plastic film and a support backing such as stainless steel. These structures offer the advantage of combining the flexure with the electrical circuit structure. The supported flexible conductors are welded to the load beam and offer both a gimbaling function and conduction of electromagnetic signals. In addition the supported flexible conductors afford electrical connection pads at various desired locations for electrical connection with the slider pads.
For very small sliders, e.g. the 30% or pico-sized slider, the bias of the twisted wire pairs is excessive. Thinner wires also are readily broken and difficult to position for automated manufacturing. The supported flexible conductor while not prone to the problems of twisted wires is problematic because it is easily damaged during device assembly by contact with tooling used to assemble the suspensions each including the load beam, the supported flexible conductor and slider into head gimbal assemblies (HGA's). The HGA is attached to the E-block, e.g. by swaging, To keep the several sliders apart wedge-shaped comb structures are inserted between the HGA's. These wedges may damage the supported flexible conductors in place on the load beams. Cleaning of the HGA may also result in damaging contact with the supported flexible conductors, and generate contamination. Also, HGA merging into the disk packs requires use of the wedge-shaped combs affording a further opportunity for physical damage to the supported physical conductors.